JP2002037980A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition capable of being utilized for an electronic circuit part and a substrate without generating the deterioration of molding property caused by a reduction of its flowing property, capable of transcribing a circuit pattern formed by a stamper in a good accuracy and capable of being extrusion molded. SOLUTION: This epoxy resin composition is characterized by using an epoxy resin, a curing agent, a curing accelerator and an inorganic filler as essential components, and containing 30-80 wt.% inorganic filler having <=10 μm maximum particle diameter, <=3 μm mean particle diameter and also 1.0-4.0 slope (n) of particle size distribution shown by a Rosin-Rammuler diagram (RRS), based on the total resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection-moldable epoxy resin composition having excellent mold transferability, and more particularly to a stamper transfer plating circuit component having a small surface roughness of a molded product and a resin for precision molding for a substrate. Composition.

[0002]

2. Description of the Related Art Epoxy resin compositions for semiconductor encapsulation or precision parts generally have a maximum particle size of 30 to 100 .mu.m.
m, and an inorganic filler having an average particle size of 3 μm or more
Since it contains 90% by weight and is excellent in adhesive strength, mechanical strength, and electrical insulation, it is widely applied to electric parts and electronic parts. However, the average particle size of the inorganic filler conventionally added is often 5 μm or more, and since the particle size of the inorganic filler is large, it is difficult to reduce the surface roughness of the molded product to 1 μm or less. It is said that it is difficult to transfer a fine pattern formed on a mold with high accuracy.

[0003] Conventionally, as the particle size of the inorganic filler becomes smaller, it becomes more difficult to increase the amount of the filler added to the resin composition, and the fluidity in the mold also becomes poor, which causes a deterioration in moldability. Had become. Furthermore, due to the properties of the epoxy resin, the epoxy resin composition lacks thermal stability around 100 ° C. Therefore, the only molding method is press molding or transfer molding. And the productivity was poor.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an injection-moldable epoxy resin composition which is excellent in mold transferability without causing deterioration in moldability due to a decrease in fluidity. The object of the present invention is to provide a product and to be used for electronic circuit components and substrate applications that will be increasingly finely patterned in the future, and to enable accurate transfer of a circuit pattern formed on a stamper. Also, since circuit formation by plating is possible,
It is an object of the present invention to provide a fine electronic circuit component and a substrate having a line and space of 10 μm by utilizing the feature that the surface roughness of a molded product is small.

[0005]

Means for Solving the Problems The present inventors have conducted various studies in order to achieve the above object, and as a result, have completed the present invention. That is, the present invention comprises an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler as main components, and has a maximum particle size of 10 μm or less, an average particle size of 3 μm or less, and is represented by a rosin-Rammler (RRS) diagram. An epoxy resin composition capable of being injection-molded, wherein the inorganic filler having a particle size distribution gradient of 1.0 to 4.0 is contained in the entire resin composition in an amount of 30 to 80% by weight. The epoxy resin composition as described above, which is spherical silica, spherical alumina, or calcium carbonate, The epoxy resin composition, wherein the epoxy resin is an ortho-cresol novolak epoxy resin, a naphthalene skeleton-containing epoxy resin, or a biphenyl skeleton-containing epoxy resin. The epoxy resin composition as described above, wherein the agent is a phenol novolak resin or an aralkylphenol resin; Agent has the general formula _{Ar-NH-CO-NR 2} (A
r is a substituted or unsubstituted aryl group, R is an alkyl group which may be the same or different), and the above-mentioned epoxy resin composition.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The epoxy resin composition of the present invention contains an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler as main components, and has a maximum particle size of 10 μm or less, an average particle size of 3 μm or less, and a rosin-Rammler (RRS). Injection-moldable epoxy resin composition characterized by containing 30 to 80% by weight in the total resin composition of an inorganic filler having a particle size distribution gradient n of 1.0 to 4.0 shown in a diagram. It is.

<Epoxy Resin> As the epoxy resin of the present invention, an ortho-cresol novolak epoxy resin, an epoxy resin having a naphthalene skeleton or an epoxy resin having a biphenyl skeleton is suitably used.
The types may be used alone, or two or more types may be used in combination at an appropriate ratio. The epoxy equivalent is 30
0 or less is preferable. In the present invention, the amount of the epoxy resin in the total resin composition is usually 5 to 30% by weight,
In particular, it is preferably in the range of 5 to 20% by weight.

<Curing Agent> The curing agent of the present invention can be used without any particular limitation as long as it reacts with the epoxy resin described above. Among them, a phenol resin is preferable, and examples of the phenol resin include a phenol novolak resin and an aralkyl phenol resin. The amount of the curing agent is 20 to 9 with respect to 100 parts by weight of the epoxy resin.
5 parts by weight, preferably 35 to 95 parts by weight, and when expressed in terms of chemical equivalent ratio, the chemical equivalent ratio to the epoxy resin is 0.5 to 1 in terms of moisture resistance and mechanical properties.
5, preferably in the range of 0.7 to 1.3.

<Curing Accelerator> The curing accelerator of the present invention promotes a crosslinking reaction between the epoxy resin and the curing agent,
In addition, a latent curing accelerator which provides thermal stability that can be injection-molded is used. Specific examples thereof include 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as D
Phenol salts abbreviated as BU), phenol novolak salts, DBU derivatives, dicyandiamide and Formula _{Ar-NH-CO-NR 2} (Ar is a substituted or unsubstituted aryl radical, R alkyl may be the same or different, such as carbonates Urea derivative represented by the formula: Above all, in order to obtain the injectable epoxy resin composition of the present invention having excellent physical properties, the formula Ar-NH-CO-NR ₂ (Ar is a substituted or unsubstituted aryl group, and R is an alkyl group which may be the same or different) It is preferable to use a urea derivative represented by the following formula:

In the epoxy resin composition of the present invention, an alkyl urea derivative represented by the following formulas (a) to (f) (Chem. 1 to Chem. 5) is used as a curing accelerator.
The stability near 0 ° C is greatly improved, and as a result, the thermal stability in the cylinder of the injection molding machine is improved.

[0011]

Embedded image (Wherein X ¹ and X ² represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a nitro group, both may be the same or different, and R represents an alkyl group which may be the same or different, respectively) The alkyl group of X ¹ and X ² is preferably a lower alkyl group having 1 to 5 carbon atoms, and the alkoxy group is preferably a lower alkoxy group having 1 to 5 carbon atoms. The alkyl group for R preferably has 1 to 1 carbon atoms.
0, particularly preferably an alkyl group having 1 to 5 carbon atoms. Compounds corresponding to this include, for example, 3-phenyl-1,1-dimethylurea, 3- (p-chlorophenyl) -1,1-dimethylurea, 3- (3,4-dichlorophenyl) -1, 1-dimethylurea, 3- (o
-Methylphenyl) -1,1-dimethylurea, 3-
(P-methylphenyl) -1,1-dimethylurea, 3
-(Methoxyphenyl) -1,1-dimethylurea, 3
-(Nitrophenyl) -1,1-dimethylurea and the like.

[0012]

Embedded image (In the formula, Y and Z each represent a hydrogen atom, a halogen atom or an alkyl group, both may be the same or different, and R represents a lower alkyl group which may be the same or different.) The alkyl group preferably has 1 to 5 carbon atoms.
Is a lower alkyl group. Examples of the compound corresponding to this include 1,1′-phenylenebis (3,3-dimethylurea) and 1,1 ′-(4-methyl-m-phenylene) -bis (3,3-dimethylurea). No.

[0013]

Embedded image (In the formula, R represents a lower alkyl group which may be the same or different.)

[0014]

Embedded image (In the formula, p represents an integer of 0 to 5, and R represents a lower alkyl group which may be the same or different.) The alkyl group of R preferably has 1 to 10 carbon atoms.
Particularly preferred is an alkyl group having 1 to 5 carbon atoms.

[0015]

Embedded image (In the above formula, R represents an alkyl group which may be the same or different.) The alkyl group of R preferably has 1 to 10 carbon atoms.
Particularly preferred is an alkyl group having 1 to 5 carbon atoms.

In the above formulas (a) to (f), X ¹ ,
Examples of the alkyl group or alkoxy group for X ² and R include a methyl group, an ethyl group, a propyl group and a butyl group,
Or an alkoxy group corresponding thereto is preferable. Also,
Examples of the compound corresponding to the formula (f) include a dimethylamine adduct of 2,4-tolylene diisocyanate [a compound in which R is a methyl group in the formula (f)]. , Is significantly used at around 100 ° C., and exhibits curing properties suitable for the injection molding of the present invention. These curing accelerators are used in an amount of 3 to 2 with respect to 100 parts by weight of the epoxy resin.
0 parts by weight, preferably 3 to 10 parts by weight.

If the potential is not impaired,
From the viewpoint of improving the molding cycle and reducing the amount of molding burrs, 2-methylimidazole and 2-ethyl-4
It is preferable to use imidazoles such as -methylimidazole and 2-heptadecylimidazole and organic phosphines such as triphenylphosphine and tri (p-methylphenyl) phosphine in combination.

<Inorganic filler> Examples of the inorganic filler used in the present invention include ferrite, graphite, calcium carbonate, alumina, silica, aluminum hydroxide, and carbon. In the present invention, silica, alumina , Calcium carbonate. In particular, a spherical silica powder having a maximum particle size of 10 μm or less, an average particle size of 3 μm or less, and a particle size distribution gradient n shown in a rosin-Rammler (RRS) diagram of 1.0 to 4.0, preferably 1.5 to 4.0 3.0 is used. Even if these inorganic fillers are alone,
Mixing may be used, and the blending amount of the entire inorganic filler in the epoxy resin composition is preferably from 30 to 80% by weight, and particularly preferably from 60 to 80% by weight.

In the present invention, rosin-Rammler (RRS)
The gradient n of the particle size distribution shown in the diagram was obtained by the following equation. n = [log (2-log R2)-｛(log (2-log R1)｝] /
[LogDp2-logDp1] Dp1: Particle size at point 1 (0.2 μm or 2 μm) Dp2: Particle size at point 2 (1 μm or 10 μm) R1: Cumulative weight% from maximum particle size to point 1 R2: From maximum particle size Cumulative weight% up to point 2. However, in the case of the silica powder used in the present invention, those having an average particle size of 10 μm or less are determined from the points of 0.2 μm and 1.0 μm in consideration of the content ratio in the entire distribution, Those having a size of 10 μm or more were determined from the points of 2 μm and 10 μm.

<Releasing Agent> Examples of the releasing agent used in the present invention include higher fatty acids such as montanic acid, stearic acid, behenic acid and oleic acid, esters of higher fatty acids such as carnauba wax (carnauba wax), and behenic acid. Zinc, zinc oleate, magnesium stearate, barium stearate, metal salts of higher fatty acids such as aluminum stearate, metal soaps such as zinc stearate, and the like, even when used alone or in combination. No problem. The compounding amount of the release agent is 0.03 to 1.0% by weight, more preferably 0.05 to 1.0% by weight in the whole resin composition.
0.8% by weight. When the amount of the release agent is within the above range, the resin composition adheres little in the cylinder of the injection molding machine and molding can be performed stably.

In addition to the above, a silane coupling agent, a brominated epoxy resin, a flame retardant such as antimony trioxide, a colorant such as carbon black and phthalocyanine, a stress reducing agent, etc. Agents, natural or synthetic waxes, and the like. In the present invention, all of these materials are heated and kneaded by a heating kneader or a hot roll, and then cooled and pulverized to obtain a desired injection-moldable epoxy resin composition.

[0022]

EXAMPLES Hereinafter, the excellent effects of the present invention will be described with reference to examples, but the present invention is not limited to the examples.
The composition was evaluated according to the following method. The results are summarized in (Table 1).

Example 1 All the raw materials shown in Table 1 were mixed with a Henschel mixer, heated and kneaded with a kneader or a roll at a temperature of 90 to 110 ° C., and further cooled and pulverized to obtain an epoxy resin composition. Was. Using this composition, according to the following method,
The values of (1) to (4) were measured.

<Evaluation method> (1) Spiral flow Using a mold having a spiral shape in accordance with the EMMI1-66 standard, transfer molding was performed, and the mold temperature was 150 ° C. and the effective pressure was 6.9 × 10. ⁶ Pa (70kgf / cm
^After molding in ² ) and curing for 180 seconds, the length flowing in the mold was measured. (2) Gel time Using Toyo Seiki Seisakusho's Labo Plast Mill,
The gel time was measured from the chart shown in FIG. 1 by the following method. After placing the sample in the device, draw a tangent to the area where the torque decreases. Next, a line is drawn parallel to the time axis in a region where the minimum torque is held. Next, the perpendicular line was lowered from the maximum torque point A, and the length from the intersection with the perpendicular line was determined, and the result was defined as the gel time. (3) Continuous moldability By injection molding, molded product size 30 mm x 6 mm, thickness 2
Using a mold having a mold length of 180 mm and a mold temperature of 180 ° C. and a molding time of 60 seconds, it is determined whether molding can be performed continuously for 1 hour or more. It was evaluated. (4) Molded product surface roughness Although several parameters of surface roughness have been proposed, two straight lines parallel to the center line of the portion extracted from the roughness curve by the reference length, when the cutout portion is sandwiched. The distance between two straight lines, that is, the maximum surface roughness Rt was measured. The measurement was performed using a surface roughness meter manufactured by Tokyo Seimitsu Co., Ltd.
In a molded product having a size of mx 6 mm and a thickness of 2 mm, a driving speed of 0.3 mm /
s and cutoff 0.8 mm.

Example 2 The procedure of Example 1 was repeated, except that the filler was changed to synthetic silica having a maximum particle size of 7 μm and an average particle size of 1.0 μm. The results are shown in (Table 1).

Example 3 The procedure of Example 1 was repeated, except that the filler was changed to synthetic silica having a maximum particle size of 8 μm and an average particle size of 1.5 μm. The results are shown in (Table 1).

Comparative Example 1 Example 1 was repeated except that the filler was changed to fused silica having a maximum particle size of 24 μm and an average particle size of 3.0 μm.
The same was done. The results are shown in (Table 1).

Comparative Example 2 Example 1 was repeated except that the filler was changed to fused silica having a maximum particle size of 64 μm and an average particle size of 6.5 μm.
The same was done. The results are shown in (Table 1).

[0029]

[Table 1] Curing accelerator: dimethylamine adduct of 2,4-tolylene diisocyanate * 1: Maximum particle size = 3 μm Average particle size = 0.5 μm RRS distribution gradient n = 2.7 * 2: {7 μm} 1.0 μm} 2.3 * 3: 〃8 μm 〃1.5 μm ２．０ 2.0 * 4: ２４24 μm 〃3.0 μm 〃1.3 * 5: 〃64 μm 〃6.5 μm １．０1.0

According to the results shown in Table 1, the epoxy resin compositions using spherical silica having an average particle diameter of 2 μm or less and an RRS distribution gradient n of 2 or more (Examples 1 to 3) have a flow represented by a spiral flow. It is possible to perform continuous molding by injection molding without greatly impairing the properties, and the molded article molded with this composition can suppress the surface roughness Rt to 1 μm or less. Compared with the composition using spherical silica having a particle size of 5 μm or more (Comparative Examples 1 and 2),
It can be seen that the surface roughness is improved. As a result, it has been found that a fine pattern formed on a stamper or the like can be transferred with high accuracy.

[0031]

Industrial Applicability The epoxy resin composition of the present invention is capable of giving a precision molded part having a small surface roughness and excellent mold transferability, and accurately transfers the surface shape formed on a stamper. it can. Therefore, it is suitable as a material for components and substrates for forming microelectronic circuits by plating after molding. Furthermore, in the epoxy resin composition of the present invention, in addition to transfer molding, continuous molding by injection molding is possible, so that the range of molding conditions can be widened.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a method for measuring a gel time.

[Description of Signs]: Tangent line at point where torque starts to decrease: Line indicating minimum torque value: Perpendicular line from point A A: Maximum torque point

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) C08K 7/18 C08K 7/18 // B29K 63:00 B29K 63:00 105: 16 105: 16 (72) Inventor Eiki Togashi 580-32 Takuji, Nagaura, Sodegaura-shi, Chiba Mitsui Chemical Co., Ltd. 4F206 AA39 AB03 AB16 AB17 JA07 JF01 JF02 JF06 4J002 CC042 CD041 CD051 CD061 CE002 DE146 DE236 DJ016 ER027 ET017 EU137 FD016 FD157 GQ01 4J036 AD07 AF05 AF08 DC25 DC31 DC41 DC46 DD07 FA01 FA02 FA05 FB06 FB07 JA07

Claims (5)

[Claims] 1. A particle having an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler as main components, a maximum particle size of 10 μm or less, an average particle size of 3 μm or less, and a rosin-Rammler (RRS) diagram. An injection-moldable epoxy resin composition comprising an inorganic filler having a distribution gradient n of 1.0 to 4.0 in the entire resin composition in an amount of 30 to 80% by weight. 2. The injection-moldable epoxy resin composition according to claim 1, wherein the inorganic filler is spherical silica, spherical alumina or calcium carbonate. 3. The epoxy resin is an ortho-cresol novolak epoxy resin, a naphthalene skeleton-containing epoxy resin or a biphenyl skeleton-containing epoxy resin.
The epoxy resin composition capable of being injection-molded according to the above. 4. The injection-moldable epoxy resin composition according to claim 1, wherein the curing agent is a phenol novolak resin or an aralkylphenol resin. 5. The method according to claim 1, wherein the curing accelerator has a general formula of Ar--NH--CO.
-NR ₂ (Ar is a substituted or unsubstituted aryl group, R represents the same or different and are an alkyl group) according to claim 1 injection moldable epoxy resin composition wherein the urea derivative represented by the.